Since prehistoric times humankind has engaged in efforts of an endless variety in attempts to purify fluids of different natures. Endeavors in this area have ranged from attempts to make brackish water drinkable to methods and devices for increasing the potency of alcoholic beverages. Various methods have been based on processes involving different miscibilities of fluids, filtration, chemical extraction processes and others. However, one of the best tried and true methods of purification has involved the evaporization and subsequent condensation of the fluid, commonly known as distillation.
Distillation is one of the primary methods for purifying brackish or otherwish impure water and also for purifying other liquids. Problems occurring with the distillation type processes are that it is difficult to handle this type of operation in a continuous flow process manner, usually a batch process method is more easily accomplished. Furthermore, distillation processes are difficult to operate when the liquid to be purified includes impurities having vaporization and condensation points very near to that of the desired liquid. Other problems with distillation processes is that they frequently require substantial external energy to be supplied in order to boil the desired liquid. Finally, distillation apparatus is frequently subject to the formation of deposits on the interior surfaces thereof from crystalized impurities, and prior art distillation mechanisms are typically difficult to clean.
Notwithstanding all of the above difficulties the distillation process has proved over time to be one of the most efficient and best understood of those available for purifying liquids. Accordingly, a large number of United States Patents have been issued on inventions relating to distillation apparati for various purposes. The majority of these patents have related to purification of either water or ethyl alcohol.
Several United States Patents are on devices utilized to purify water utilizing a boiling technique and a cooling column for recondensing the vaporized liquid. Two examples of this approach are found in U.S. Pat. No. 4,601,789, issued to J. G. Bjorklund for a "Water Purification Apparatus" and U.S. Pat. No. 4,690,102, issued to G. Sundquist for "Water Heater and Distiller Apparatus". Other devices have primarily utilized the concept of preheating the incoming fluid by contact, either directly or through heat exchange mechanisms, with the already heated vapor. Devices of this type are reflected in U.S. Pat. No. 4,342,625, issued to C. C. Dennison for a "Modular Automatic Water Distiller" and in U.S. Pat. No. 4,687,550, issued to M. J. Wong for a "Water Distiller".
Another conceptual approach to enhancing the efficacy of water distilling techniques is the use of varying pressure on the components to enhance vaporization and condensation phase changes. An example of this approach is found in U.S. Pat. No. 4,686,009, issued to D. L. McCabe for a "Distillation System".
Another conceptual approach is to cause the fluids to pass through a convoluted series of plates which will either heat or cool the fluids as they pass the plate surfaces. Some examples of this approach are found in U.S. Pat. No. 4,585,524, issued to J. Hoiss for a "Method and Apparatus for Distillation of Crude Water", an apparatus which is applicable to demineralized fluid, U.S. Pat. No. 4,475,988, issued K. Tsumura, et al., for a "Process for Distilling Water and Distillation Apparatus", which utilizes alternating hot and cold plates, and in U.S. Pat. No. 3,398,060, issued to J. J. Cowley, for a "Process for Continous Regenerative Distillation of Impure Water", which utilized expanding or decreasing volumes to modify the pressure in addition to a convolution scheme.
Although each of the prior art devices discussed above and many others which are found in the art are effective for various particular purposes, all suffer from one or more of the above stated disadvantages. Accordingly, there remains substantial ground for improvement of the process, particularily in an low-end encomical procedure.